Pharmacological modulation of RB1 activity mitigates resistance to neoadjuvant chemotherapy in locally advanced rectal cancer.

Resistance to neoadjuvant chemotherapy leads to poor prognosis of locally advanced rectal cancer (LARC), representing an unmet clinical need that demands further exploration of therapeutic strategies to improve clinical outcomes. Here, we identified a noncanonical role of RB1 for modulating chromatin activity that contributes to oxaliplatin resistance in colorectal cancer (CRC). We demonstrate that oxaliplatin induces RB1 phosphorylation, which is associated with the resistance to neoadjuvant oxaliplatin-based chemotherapy in LARC. Inhibition of RB1 phosphorylation by CDK4/6 inhibitor results in vulnerability to oxaliplatin in both intrinsic and acquired chemoresistant CRC. Mechanistically, we show that RB1 modulates chromatin activity through the TEAD4/HDAC1 complex to epigenetically suppress the expression of DNA repair genes. Antagonizing RB1 phosphorylation through CDK4/6 inhibition enforces RB1/TEAD4/HDAC1 repressor activity, leading to DNA repair defects, thus sensitizing oxaliplatin treatment in LARC. Our study identifies a RB1 function in regulating chromatin activity through TEAD4/HDAC1. It also provides the combination of CDK4/6 inhibitor with oxaliplatin as a potential synthetic lethality strategy to mitigate oxaliplatin resistance in LARC, whereby phosphorylated RB1/TEAD4 can serve as potential biomarkers to guide the patient stratification.

Subtyping and prognostic model construction based on vesicle-mediated transport-related genes in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is impacted by various environmental and genetic variables. Dysregulation of vesicle-mediated transport-related genes (VMTRGs) has been observed in many malignancies, but their effect on prognosis in CRC remains unclear. METHODS: CRC samples were clustered into varying subtypes per differential expression of VMTRGs. R package was utilized to explore differences in survival, immune, and drug sensitivity among different disease subtypes. According to differentially expressed genes (DEGs) between subtypes, regression analysis was employed to build a riskscore model and identify independent prognostic factors. The model was validated through a Gene Expression Omnibus (GEO) dataset. Immune landscape, immunophenoscore (IPS), and Tumor Immune Dysfunction and Exclusion (TIDE) scores for different risk groups were calculated. RESULTS: Two subtypes of CRC were identified based on VMTRGs, which showed significant differences in survival rates, immune cell infiltration abundance, immune functional activation levels, and immune checkpoint expression levels. Cluster2 exhibited higher sensitivity to anti-tumor drugs such as Nilotinib, Cisplatin, and Oxaliplatin compared to Cluster1. DEGs were mainly enriched in biological processes such as epidermis development, epidermal cell differentiation, and receptor-ligand activity, and signaling pathways like pancreatic secretion. The constructed 13-gene riskscore model demonstrated good predictive ability for CRC patients' prognosis. Furthermore, differences in immune landscape, IPS, and TIDE scores were observed among different risk groups. CONCLUSION: This study successfully obtained two CRC subtypes with distinct survival statuses and immune levels based on differential expression of VMTRGs. A 13-gene risk model was constructed. The findings had important implications for prognosis and treatment of CRC.

Preoperative Treatment of Locally Advanced Rectal Cancer.

BACKGROUND: Pelvic radiation plus sensitizing chemotherapy with a fluoropyrimidine (chemoradiotherapy) before surgery is standard care for locally advanced rectal cancer in North America. Whether neoadjuvant chemotherapy with fluorouracil, leucovorin, and oxaliplatin (FOLFOX) can be used in lieu of chemoradiotherapy is uncertain. METHODS: We conducted a multicenter, unblinded, noninferiority, randomized trial of neoadjuvant FOLFOX (with chemoradiotherapy given only if the primary tumor decreased in size by <20% or if FOLFOX was discontinued because of side effects) as compared with chemoradiotherapy. Adults with rectal cancer that had been clinically staged as T2 node-positive, T3 node-negative, or T3 node-positive who were candidates for sphincter-sparing surgery were eligible to participate. The primary end point was disease-free survival. Noninferiority would be claimed if the upper limit of the two-sided 90.2% confidence interval of the hazard ratio for disease recurrence or death did not exceed 1.29. Secondary end points included overall survival, local recurrence (in a time-to-event analysis), complete pathological resection, complete response, and toxic effects. RESULTS: From June 2012 through December 2018, a total of 1194 patients underwent randomization and 1128 started treatment; among those who started treatment, 585 were in the FOLFOX group and 543 in the chemoradiotherapy group. At a median follow-up of 58 months, FOLFOX was noninferior to chemoradiotherapy for disease-free survival (hazard ratio for disease recurrence or death, 0.92; 90.2% confidence interval [CI], 0.74 to 1.14; P = 0.005 for noninferiority). Five-year disease-free survival was 80.8% (95% CI, 77.9 to 83.7) in the FOLFOX group and 78.6% (95% CI, 75.4 to 81.8) in the chemoradiotherapy group. The groups were similar with respect to overall survival (hazard ratio for death, 1.04; 95% CI, 0.74 to 1.44) and local recurrence (hazard ratio, 1.18; 95% CI, 0.44 to 3.16). In the FOLFOX group, 53 patients (9.1%) received preoperative chemoradiotherapy and 8 (1.4%) received postoperative chemoradiotherapy. CONCLUSIONS: In patients with locally advanced rectal cancer who were eligible for sphincter-sparing surgery, preoperative FOLFOX was noninferior to preoperative chemoradiotherapy with respect to disease-free survival. (Funded by the National Cancer Institute; PROSPECT ClinicalTrials.gov number, NCT01515787.).

Circulating Tumor DNA Analysis Guiding Adjuvant Therapy in Stage II Colon Cancer.

BACKGROUND: The role of adjuvant chemotherapy in stage II colon cancer continues to be debated. The presence of circulating tumor DNA (ctDNA) after surgery predicts very poor recurrence-free survival, whereas its absence predicts a low risk of recurrence. The benefit of adjuvant chemotherapy for ctDNA-positive patients is not well understood. METHODS: We conducted a trial to assess whether a ctDNA-guided approach could reduce the use of adjuvant chemotherapy without compromising recurrence risk. Patients with stage II colon cancer were randomly assigned in a 2:1 ratio to have treatment decisions guided by either ctDNA results or standard clinicopathological features. For ctDNA-guided management, a ctDNA-positive result at 4 or 7 weeks after surgery prompted oxaliplatin-based or fluoropyrimidine chemotherapy. Patients who were ctDNA-negative were not treated. The primary efficacy end point was recurrence-free survival at 2 years. A key secondary end point was adjuvant chemotherapy use. RESULTS: Of the 455 patients who underwent randomization, 302 were assigned to ctDNA-guided management and 153 to standard management. The median follow-up was 37 months. A lower percentage of patients in the ctDNA-guided group than in the standard-management group received adjuvant chemotherapy (15% vs. 28%; relative risk, 1.82; 95% confidence interval [CI], 1.25 to 2.65). In the evaluation of 2-year recurrence-free survival, ctDNA-guided management was noninferior to standard management (93.5% and 92.4%, respectively; absolute difference, 1.1 percentage points; 95% CI, -4.1 to 6.2 [noninferiority margin, -8.5 percentage points]). Three-year recurrence-free survival was 86.4% among ctDNA-positive patients who received adjuvant chemotherapy and 92.5% among ctDNA-negative patients who did not. CONCLUSIONS: A ctDNA-guided approach to the treatment of stage II colon cancer reduced adjuvant chemotherapy use without compromising recurrence-free survival. (Supported by the Australian National Health and Medical Research Council and others; DYNAMIC Australian New Zealand Clinical Trials Registry number, ACTRN12615000381583.).

Immunogenic Chemotherapy Sensitizes Tumors to Checkpoint Blockade Therapy.

Checkpoint blockade immunotherapies can be extraordinarily effective, but might benefit only the minority of patients whose tumors are pre-infiltrated by T cells. Here, using lung adenocarcinoma mouse models, including genetic models, we show that autochthonous tumors that lacked T cell infiltration and resisted current treatment options could be successfully sensitized to host antitumor T cell immunity when appropriately selected immunogenic drugs (e.g., oxaliplatin combined with cyclophosphamide for treatment against tumors expressing oncogenic Kras and lacking Trp53) were used. The antitumor response was triggered by direct drug actions on tumor cells, relied on innate immune sensing through toll-like receptor 4 signaling, and ultimately depended on CD8(+) T cell antitumor immunity. Furthermore, instigating tumor infiltration by T cells sensitized tumors to checkpoint inhibition and controlled cancer durably. These findings indicate that the proportion of cancers responding to checkpoint therapy can be feasibly and substantially expanded by combining checkpoint blockade with immunogenic drugs.

Role of pattern recognition receptors in chemotherapy-induced neuropathic pain.

Progress in the development of effective chemotherapy is producing a growing population of patients with acute and chronic painful chemotherapy-induced peripheral neuropathy (CIPN), a serious treatment-limiting side effect for which there is currently no US Food and Drug Administration-approved treatment. CIPNs induced by diverse classes of chemotherapy drugs have remarkably similar clinical presentations, leading to the suggestion they share underlying mechanisms. Sensory neurons share with immune cells the ability to detect damage associated molecular patterns (DAMPs), molecules produced by diverse cell types in response to cellular stress and injury, including by chemotherapy drugs. DAMPs, in turn, are ligands for pattern recognition receptors (PRRs), several of which are found on sensory neurons, as well as satellite cells, and cells of the immune system. In the present experiments, we evaluated the role of two PRRs, TLR4 and RAGE, present in dorsal root ganglion (DRG), in CIPN. Antisense (AS)-oligodeoxynucleotides (ODN) against TLR4 and RAGE mRNA were administered intrathecally before ('prevention protocol') or 3 days after ('reversal protocol') the last administration of each of three chemotherapy drugs that treat cancer by different mechanisms (oxaliplatin, paclitaxel and bortezomib). TLR4 and RAGE AS-ODN prevented the development of CIPN induced by all three chemotherapy drugs. In the reversal protocol, however, while TLR4 AS-ODN completely reversed oxaliplatin- and paclitaxel-induced CIPN, in rats with bortezomib-induced CIPN it only produced a temporary attenuation. RAGE AS-ODN, in contrast, reversed CIPN induced by all three chemotherapy drugs. When a TLR4 antagonist was administered intradermally to the peripheral nociceptor terminal, it did not affect CIPN induced by any of the chemotherapy drugs. However, when administered intrathecally, to the central terminal, it attenuated hyperalgesia induced by all three chemotherapy drugs, compatible with a role of TLR4 in neurotransmission at the central terminal but not sensory transduction at the peripheral terminal. Finally, since it has been established that cultured DRG neurons can be used to study direct effects of chemotherapy on nociceptors, we also evaluated the role of TLR4 in CIPN at the cellular level, using patch-clamp electrophysiology in DRG neurons cultured from control and chemotherapy-treated rats. We found that increased excitability of small-diameter DRG neurons induced by in vivo and in vitro exposure to oxaliplatin is TLR4-dependent. Our findings suggest that in addition to the established contribution of PRR-dependent neuroimmune mechanisms, PRRs in DRG cells also have an important role in CIPN.

Circumventing drug resistance in gastric cancer: A spatial multi-omics exploration of chemo and immuno-therapeutic response dynamics.

BACKGROUND: Gastric Cancer (GC) characteristically exhibits heterogeneous responses to treatment, particularly in relation to immuno plus chemo therapy, necessitating a precision medicine approach. This study is centered around delineating the cellular and molecular underpinnings of drug resistance in this context. METHODS: We undertook a comprehensive multi-omics exploration of postoperative tissues from GC patients undergoing the chemo and immuno-treatment regimen. Concurrently, an image deep learning model was developed to predict treatment responsiveness. RESULTS: Our initial findings associate apical membrane cells with resistance to fluorouracil and oxaliplatin, critical constituents of the therapy. Further investigation into this cell population shed light on substantial interactions with resident macrophages, underscoring the role of intercellular communication in shaping treatment resistance. Subsequent ligand-receptor analysis unveiled specific molecular dialogues, most notably TGFB1-HSPB1 and LTF-S100A14, offering insights into potential signaling pathways implicated in resistance. Our SVM model, incorporating these multi-omics and spatial data, demonstrated significant predictive power, with AUC values of 0.93 and 0.84 in the exploration and validation cohorts respectively. Hence, our results underscore the utility of multi-omics and spatial data in modeling treatment response. CONCLUSION: Our integrative approach, amalgamating mIHC assays, feature extraction, and machine learning, successfully unraveled the complex cellular interplay underlying drug resistance. This robust predictive model may serve as a valuable tool for personalizing therapeutic strategies and enhancing treatment outcomes in gastric cancer.

Prevention of allergic reactions during oxaliplatin desensitization through inhibition of Bruton tyrosine kinase.

BACKGROUND: Acute infusion reactions to oxaliplatin, a chemotherapeutic used to treat gastrointestinal cancers, are observed in about 20% of patients. Rapid drug desensitization (RDD) protocols often allow the continuation of oxaliplatin in patients with no alternative options. Breakthrough symptoms, including anaphylaxis, can still occur during RDD. OBJECTIVE: Our aim was to evaluate whether pretreatment with acalabrutinib, a Bruton tyrosine kinase inhibitor, can prevent anaphylaxis during RDD in a patient sensitized to oxaliplatin. METHODS: A 52-year-old male with locally advanced gastric carcinoma developed anaphylaxis during his fifth cycle of oxaliplatin. As he required 6 additional cycles to complete his curative-intent treatment regimen, he underwent RDD to oxaliplatin but still developed severe acute reactions. The risks and benefits of adding acalabrutinib before and during RDD were reviewed, and the patient elected to proceed. RESULTS: With acalabrutinib taken before and during the RDD, the patient was able to tolerate oxaliplatin RDD without complication. Consistent with its mechanism of action, acalabrutinib completely blocked the patient's positive skin prick response to oxaliplatin. Acalabrutinib did not alter the percentage of circulating basophils (1.24% vs 0.98%) before the RDD but did protect against basopenia (0.74% vs 0.09%) after the RDD. Acalabrutinib was associated with a drastic reduction in the ability of basophils to upregulate CD63 in vitro following incubation with oxaliplatin (0.11% vs 2.38%) or polyclonal anti-human IgE antibody (0.08% vs 44.2%). CONCLUSIONS: Five doses of acalabrutinib, 100 mg, orally twice daily starting during the evening 2 days before and continuing through RDD allowed a sensitized patient to receive oxaliplatin successfully and safely.

Combining CD40 agonist mitazalimab with mFOLFIRINOX in previously untreated metastatic pancreatic ductal adenocarcinoma (OPTIMIZE-1): a single-arm, multicentre phase 1b/2 study.

BACKGROUND: Current systemic therapies for metastatic pancreatic ductal adenocarcinoma are associated with poor outcomes with a 5-year overall survival rate under 5%. We aimed to assess the safety and antitumour activity of mitazalimab, a human CD40 agonistic IgG1 antibody, with modified FOLFIRINOX (mFOLFIRINOX; fluorouracil, leucovorin, oxaliplatin, and irinotecan), in chemotherapy-naive patients with metastatic pancreatic ductal adenocarcinoma. METHODS: OPTIMIZE-1 was a single-arm, multicentre, phase 1b/2 study which enrolled adults with histologically-confirmed metastatic pancreatic ductal adenocarcinoma and European Cooperative Oncology Group performance status 0 or 1 in 14 university hospitals in Belgium, France, and Spain. The primary endpoint of phase 1b was to determine the recommended phase 2 dose of intravenous mitazalimab (450 µg/kg or 900 µg/kg) when combined with intravenous mFOLFIRINOX (oxaliplatin 85 mg/m2, leucovorin 400 mg/m2, irinotecan 150 mg/m2, fluorouracil 2400 mg/m2). In the first 21-day treatment cycle, mitazalimab was administered on days 1 and 10, and mFOLFIRINOX on day 8. In subsequent 14-day cycles mitazalimab was administered 2 days after mFOLFIRINOX. The phase 2 primary endpoint was objective response rate. Activity and safety analyses were conducted on the full analysis set (all patients who received the combination of mitazalimab at the recommended phase 2 dose and mFOLFIRINOX for at least two treatment cycles) and safety set (all patients who received any study treatment), respectively. Enrolment is complete, and data represents a primary analysis of the ongoing trial. The trial is registered at Clinicaltrials.gov (NCT04888312). FINDINGS: Between Sept 29, 2021, and March 28, 2023, 88 patients were screened and 70 patients were enrolled (40 [57%] were female and 30 [43%] were male). In phase 1b, 900 µg/kg mitazalimab was determined as the recommended phase 2 dose. Overall, five patients received 450 µg/kg mitazalimab; 65 received 900 µg/kg mitazalimab. No dose-limiting toxicities were observed at 450 µg/kg, and one dose-limiting toxicity was observed at 900 µg/kg. 57 patients were evaluated for activity, and all 70 patients were included in the safety set. At data cutoff on Nov 14, 2023, median follow-up was 12·7 months (95% CI 11·1-15·7). Of the 57 patients, 29 (51%) remained on study and 18 (32%) remained on treatment. The primary endpoint (objective response rate >30%) was met (objective response rates in 23 [40%]; one-sided 90% CI ≥32 of 57 patients). The most common grade 3 or worse adverse events were neutropenia (18 [26%] of 70 patients), hypokalaemia (11 patients [16%]), and anaemia and thrombocytopenia (eight patients [11%]). Serious adverse events were reported in 29 (41%) of 70 patients, the most common being vomiting (five [7%] of 70 patients), decreased appetite (four [6%]), and diarrhoea and cholangitis (three [4%] of 70 patients for each), none considered related to mitazalimab. No treatment-related deaths were reported. INTERPRETATION: Mitazalimab with mFOLFIRINOX demonstrated manageable safety and encouraging activity, warranting continued development in a phase 3, randomised, controlled trial. The results from OPTIMIZE-1 pave the way for further exploration and confirmation of a novel immunotherapy treatment regimen for metastatic pancreatic ductal adenocarcinoma, which is a complex and aggressive cancer with very low survival rates and restricted treatment options. FUNDING: Alligator Bioscience.

Parkin-mediated mitophagy is a potential treatment for oxaliplatin-induced peripheral neuropathy.

Oxaliplatin-induced peripheral nerve pain (OIPNP) is a common chemotherapy-related complication, but the mechanism is complex. Mitochondria are vital for cellular homeostasis and regulating oxidative stress. Parkin-mediated mitophagy is a cellular process that removes damaged mitochondria, exhibiting a protective effect in various diseases; however, its role in OIPNP remains unclear. In this study, we found that Parkin-mediated mitophagy was decreased, and reactive oxygen species (ROS) was upregulated in OIPNP rat dorsal root ganglion (DRG) in vivo and in PC12 cells stimulated with oxaliplatin (OXA) in vitro. Overexpression of Parkin indicated that OXA might cause mitochondrial and cell damage by inhibiting mitophagy. We also showed that salidroside (SAL) upregulated Parkin-mediated mitophagy to eliminate damaged mitochondria and promote PC12 cell survival. Knockdown of Parkin indicated that mitophagy is crucial for apoptosis and mitochondrial homeostasis in PC12 cells. In vivo study also demonstrated that SAL enhances Parkin-mediated mitophagy in the DRG and alleviates peripheral nerve injury and pain. These results suggest that Parkin-mediated mitophagy is involved in the pathogenesis of OIPNP and may be a potential therapeutic target for OIPNP.NEW & NOTEWORTHY This article discusses the effects and mechanisms of Parkin-mediated mitophagy in oxaliplatin-induced peripheral nerve pain (OIPNP) from both in vivo and in vitro. We believe that our study makes a significant contribution to the literature because OIPNP has always been the focus of clinical medicine, and mitochondrial quality regulation mechanisms especially Parkin-mediated mitophagy, have been deeply studied in recent years. We use a variety of molecular biological techniques and animal experiments to support our argument.

The rational modulation of autophagy sensitizes colorectal cancer cells to 5-fluouracil and oxaliplatin.

Colorectal cancer (CRC) is the third most common and deadliest cancer globally. Regimens using 5-fluorouracil (5FU) and Oxaliplatin (OXA) are the first-line treatment for CRC, but tumor recurrence is frequent. It is plausible to hypothesize that differential cellular responses are triggered after treatments depending on the genetic background of CRC cells and that the rational modulation of cell tolerance mechanisms like autophagy may reduce the regrowth of CRC cells. This study proposes investigating the cellular mechanisms triggered by CRC cells exposed to 5FU and OXA using a preclinical experimental design mimicking one cycle of the clinical regimen (i.e., 48 h of treatment repeated every 2 weeks). To test this, we treated CRC human cell lines HCT116 and HT29 with the 5FU and OXA, combined or not, for 48 h, followed by analysis for two additional weeks. Compared to single-drug treatments, the co-treatment reduced tumor cell regrowth, clonogenicity and stemness, phenotypes associated with tumor aggressiveness and poor prognosis in clinics. This effect was exerted by the induction of apoptosis and senescence only in the co-treatment. However, a week after treatment, cells that tolerated the treatment had high levels of autophagy features and restored the proliferative phenotype, resembling tumor recurrence. The pharmacologic suppression of early autophagy during its peak of occurrence, but not concomitant with chemotherapeutics, strongly reduced cell regrowth. Overall, our experimental model provides new insights into the cellular mechanisms that underlie the response and tolerance of CRC cells to 5FU and OXA, suggesting optimized, time-specific autophagy inhibition as a new avenue for improving the efficacy of current treatments.

Gastric cancer mesenchymal stem cells promote tumor glycolysis and chemoresistance by regulating B7H3 in gastric cancer cells.

Despite surgical treatment combined with multidrug therapy having made some progress, chemotherapy resistance is the main cause of recurrence and death of gastric cancer (GC). Gastric cancer mesenchymal stem cells (GCMSCs) have been reported to be correlated with the limited efficacy of chemotherapy in GC, but the mechanism of GCMSCs regulating GC resistance needs to be further studied. The gene set enrichment analysis (GSEA) was performed to explore the glycolysis-related pathways heterogeneity across different cell subpopulations. Glucose uptake and lactate production assays were used to evaluate the importance of B7H3 expression in GCMSCs-treated GC cells. The therapeutic efficacy of oxaliplatin (OXA) and paclitaxel (PTX) was determined using CCK-8 and colony formation assays. Signaling pathways altered by GCMSCs-CM were revealed by immunoblotting. The expression of TNF-α in GCMSCs and bone marrow mesenchymal stem cells (BMMSCs) was detected by western blot analysis and qPCR. Our results showed that the OXA and PTX resistance of GC cells were significantly enhanced in the GCMSCs-CM treated GC cells. Acquired OXA and PTX resistance was characterized by increased cell viability for OXA and PTX, the formation of cell colonies, and decreased levels of cell apoptosis, which were accompanied by reduced levels of cleaved caspase-3 and Bax expression, and increased levels of Bcl-2, HK2, MDR1, and B7H3 expression. Blocking TNF-α in GCMSCs-CM, B7H3 knockdown or the use of 2-DG, a key enzyme inhibitor of glycolysis in GC cells suppressed the OXA and PTX resistance of GC cells that had been treated with GCMSCs-CM. This study shows that GCMSCs-CM derived TNF-α could upregulate the expression of B7H3 of GC cells to promote tumor chemoresistance. Our results provide a new basis for the treatment of GC.

Phase I trial of apatinib and paclitaxel+oxaliplatin+5-FU/levoleucovorin for treatment-naïve advanced gastric cancer.

Chinese guidelines recommend POF (paclitaxel, oxaliplatin, and 5-FU/levoleucovorin) as first-line treatment for advanced gastric cancer (AGC). Apatinib can augment the antitumor effect of paclitaxel, oxaliplatin, or fluorouracil in preclinical studies of AGC. A phase I clinical trial was conducted to evaluate the anticancer activity and maximum tolerated dose (MTD) of apatinib plus POF in treatment-naïve patients with AGC and to establish a recommended phase II dose. Participants received escalating doses of daily oral apatinib (250, 375, 500, 625, 750, and 850 mg) plus POF every 2 weeks using a conventional "3 + 3" study design. Among 21 treated patients, one experienced a dose-limiting toxicity (grade 3 skin ulceration at 850 mg). No MTD was reached. Apatinib 750 mg plus POF was recommended for phase II study. The most common grade 3-4 adverse events (AEs) were neutropenia (33.3%), mucositis (14.3%), and hand-foot syndrome (14.3%). Median progression-free and overall survival were 10.4 months (95% CI: 6.3, 14.6) and 18.4 months (95% CI: 9.8, 28.2), respectively. Apatinib up to 850 mg coadministered with POF was well tolerated with manageable AEs. The safety and anticancer activity of this regimen warrants its further investigation as first-line treatment for AGC in a larger study.

First-line oxaliplatin-based chemotherapy and nivolumab for metastatic microsatellite-stable colorectal cancer-the randomised METIMMOX trial.

BACKGROUND: We evaluated first-line treatment of metastatic microsatellite-stable colorectal cancer with short-course oxaliplatin-based chemotherapy alternating with immune checkpoint blockade. METHODS: Patients were randomly assigned to chemotherapy (the FLOX regimen; control group) or alternating two cycles each of FLOX and nivolumab (experimental group). Radiographic response assessment was done every eight weeks with progression-free survival (PFS) as the primary endpoint. Cox proportional-hazards regression models estimated associations between PFS and relevant variables. A post hoc analysis explored C-reactive protein as signal of responsiveness to immune checkpoint blockade. RESULTS: Eighty patients were randomised and 38 in each group received treatment. PFS was comparable-control group: median 9.2 months (95% confidence interval (CI), 6.3-12.7); experimental group: median 9.2 months (95% CI, 4.5-15.0). The adjusted Cox model revealed that experimental-group subjects aged ≥60 had significantly lowered progression risk (p = 0.021) with hazard ratio 0.17 (95% CI, 0.04-0.76). Experimental-group patients with C-reactive protein <5.0 mg/L when starting nivolumab (n = 17) reached median PFS 15.8 months (95% CI, 7.8-23.7). One-sixth of experimental-group cases (all KRAS/BRAF-mutant) achieved complete response. CONCLUSIONS: The investigational regimen did not improve the primary outcome for the intention-to-treat population but might benefit small subgroups of patients with previously untreated, metastatic microsatellite-stable colorectal cancer. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT03388190 (02/01/2018).

High pyroptosis activity in pancreatic adenocarcinoma: poor prognosis and oxaliplatin resistance.

BACKGROUND: Pyroptosis, as a type of inflammatory programmed cell death, has been studied in inflammatory diseases and numerous cancers but its role in pancreatic ductal adenocarcinoma (PDAC) remains further exploration. METHODS: A TCGA-PDAC cohort was enrolled for bioinformatics analysis to investigate the effect of pyroptosis on the prognosis and drug sensitivity of patients. PA-TU-8988T and CFPAC-1 cells were selected for investigating the role of GSDMC in PDAC. RESULTS: A distinct classification pattern of PDAC mediated by 21 pyroptosis-related genes (PRGs) was identified. It was suggested that higher pyroptosis activity was associated with poor prognosis of patients and higher tumor proliferation rates. We further established a prognostic model based on three PRGs (GSDMC, CASP4 and NLRP1) and the TCGA-PDAC cohort was classified into low and high-risk subgroups. It is noteworthy that the high-risk group showed significantly higher tumor proliferation rates and was proved to be highly correlated with oxaliplatin resistance. Further experiments suggested that overexpression of GSDMC promoted the proliferation and oxaliplatin resistance of PA-TU-8988T cells in vitro and vivo, while downregulation of GSDMC showed opposite effects in CFPAC-1 cells. Finally, we found that the activation of pentose phosphate pathway (PPP) was the mechanism by which GSDMC overexpression promoted the proliferation and oxaliplatin resistance of pancreatic cancer cells. CONCLUSIONS: In this study, we found that higher pyroptosis activity is associated with worse prognosis and oxaliplatin resistance of PDAC patients. In addition, as a core effector of pyroptosis, GSDMC promoted proliferation and oxaliplatin resistance of pancreatic cancer cells, which will provide new therapeutic target for PDAC patients.

SNHG4-mediated PTEN destabilization confers oxaliplatin resistance in colorectal cancer cells by inhibiting ferroptosis.

Oxaliplatin resistance poses a significant challenge in colorectal cancer (CRC) therapy, necessitating further investigation into the underlying molecular mechanisms. This study aimed to elucidate the regulatory role of SNHG4 in oxaliplatin resistance and ferroptosis in CRC. Our findings revealed that treatment with oxaliplatin led to downregulation of SNHG4 expression in CRC cells, while resistant CRC cells exhibited higher levels of SNHG4 compared to parental cells. Silencing SNHG4 attenuated oxaliplatin resistance and reduced the expression of resistance-related proteins MRD1 and MPR1. Furthermore, induction of ferroptosis effectively diminished oxaliplatin resistance in both parental and resistant CRC cells. Notably, ferroptosis induction resulted in decreased SNHG4 expression, whereas SNHG4 overexpression suppressed ferroptosis. Through FISH, RIP, and RNA pull-down assays, we identified the cytoplasmic localization of both SNHG4 and PTEN, establishing that SNHG4 directly targets PTEN, thereby reducing mRNA stability in CRC cells. Silencing PTEN abrogated the impact of SNHG4 on oxaliplatin resistance and ferroptosis in CRC cells. In vivo experiments further validated the influence of SNHG4 on oxaliplatin resistance and ferroptosis in CRC cells through PTEN regulation. In conclusion, SNHG4 promotes resistance to oxaliplatin in CRC cells by suppressing ferroptosis through instability of PTEN, thus serves as a target for patients with oxaliplatin-base chemoresistance.

ß-hydroxybutyrate resensitizes colorectal cancer cells to oxaliplatin by suppressing H3K79 methylation in vitro and in vivo.

BACKGROUND: Ketone ß-hydroxybutyrate (BHB) has been reported to prevent tumor cell proliferation and improve drug resistance. However, the effectiveness of BHB in oxaliplatin (Oxa)-resistant colorectal cancer (CRC) and the underlying mechanism still require further proof. METHODS: CRC-Oxa-resistant strains were established by increasing concentrations of CRC cells to Oxa. CRC-Oxa cell proliferation, apoptosis, invasion, migration, and epithelial-mesenchymal transition (EMT) were checked following BHB intervention in vitro. The subcutaneous and metastasis models were established to assess the effects of BHB on the growth and metastasis of CRC-Oxa in vivo. Eight Oxa responders and seven nonresponders with CRC were enrolled in the study. Then, the serum BHB level and H3K79me, H3K27ac, H3K14ac, and H3K9me levels in tissues were detected. DOT1L (H3K79me methyltransferase) gene knockdown or GNE-049 (H3K27ac inhibitor) use was applied to analyze further whether BHB reversed CRC-Oxa resistance via H3K79 demethylation and/or H3K27 deacetylation in vivo and in vitro. RESULTS: Following BHB intervention based on Oxa, the proliferation, migration, invasion, and EMT of CRC-Oxa cells and the growth and metastasis of transplanted tumors in mice were suppressed. Clinical analysis revealed that the differential change in BHB level was associated with drug resistance and was decreased in drug-resistant patient serum. The H3K79me, H3K27ac, and H3K14ac expressions in CRC were negatively correlated with BHB. Furthermore, results indicated that H3K79me inhibition may lead to BHB target deletion, resulting in its inability to function. CONCLUSIONS: ß-hydroxybutyrate resensitized CRC cells to Oxa by suppressing H3K79 methylation in vitro and in vivo.

A Somatic BRCA2-Mutated Pancreatic Adenocarcinoma With Sustained Exceptional Response to Modified FOLFIRINOX.

Homologous recombination repair (HRR) pathway deficiency opens multiple therapeutic avenues within pancreatic cancer. Patients with HRR deficiency-associated gene mutations such as BRCA1, BRCA2, and PALB2 are more susceptible to platinum-based chemotherapies and in those with somatic BRCA mutations, PARP inhibitor therapy prolongs progression-free survival. The case discussed herein illustrates the therapeutic opportunities offered through the identification of HRR deficiency in pancreatic cancer, as well as the challenges associated with treatment and prevention of central nervous system metastases in long-term survivors of pancreatic cancer.

Trifluridine/Tipiracil Plus Bevacizumab for Vulnerable Patients With Pretreated Metastatic Colorectal Cancer: A Retrospective Study (WJOG14520G).

BACKGROUND: Trifluridine/tipiracil (FTD/TPI) plus bevacizumab has shown clinical benefit for metastatic colorectal cancer (mCRC) refractory to standard therapy. However, few data have been available for patients with pretreated mCRC who are intolerant of intensive therapy (vulnerable). METHODS: We performed a multicenter retrospective study (WJOG14520G; TWILIGHT) of FTD/TPI plus bevacizumab for vulnerable patients with pretreated mCRC. Eligibility criteria included previous chemotherapy (although patients treated with all key cytotoxic agents, a fluoropyrimidine, oxaliplatin, and irinotecan, were excluded) and intolerance of full-dose combination therapy with oxaliplatin or irinotecan at the start of FTD/TPI plus bevacizumab. RESULTS: The median age of 93 evaluable patients was 79 years (range, 21-90). Intolerance of intensive therapy was attributable to an older age in 60 (65%) patients, serious concomitant disease in 24 (26%) patients, and a poor performance status in 19 (20%) patients. FTD/TPI plus bevacizumab was administered as second-line treatment in 74 (80%) patients and as third- or fourth-line treatment in 19 (20%) patients. The objective response rate was 4.9% (95% confidence interval [CI], 1.4%-12.2%), and the disease control rate was 67.9% (95% CI, 56.6%-77.8%). With a median follow-up time of 21.6 months, median overall survival and progression-free survival were 18.6 months (95% CI, 12.1-23.2) and 6.3 months (95% CI, 5.0-8.3), respectively. Neutropenia of grade ≥3 developed in 50 (54%) patients, whereas 2 (2%) patients experienced febrile neutropenia, and no treatment-related death was observed. CONCLUSION: Our data show the potential efficacy and acceptable safety profile of FTD/TPI plus bevacizumab for vulnerable patients with pretreated mCRC.

Computational assessment of the use of graphene-based nanosheets as PtII chemotherapeutics delivery systems.

Graphene is the newest form of elemental carbon and it is becoming rapidly a potential candidate in the framework of nano-bio research. Many reports confirm the successful use of graphene-based materials as carriers of anticancer drugs having relatively high loading capacities compared with other nanocarriers. Here, the outcomes of a systematic study of the adsorption behavior of FDA approved PtII drugs cisplatin, oxaliplatin, and carboplatin on surface models of pristine, holey, and nitrogen-doped holey graphene are reported. DFT investigations in water solvent have been carried out considering several initial orientations of the drugs with respect to the surfaces. Adsorption free energies, calculated including basis set superposition error (BSSE) corrections, result to be significantly negative for many of the drug@carrier adducts indicating that tested layers could be used as potential carriers for the delivery of anticancer PtII drugs. The reduced density gradient (RDG) analysis allows to show that many kinds of non-covalent interactions, including canonical H-bond, are responsible for the stabilization of the formed adducts.